Protective wiring device

ABSTRACT

The present invention is directed to electrical wiring device that includes: a housing assembly including a cover assembly and a back body member, the cover assembly including a front cover having a plurality of receptacle openings, the housing assembly further including a plurality of line terminals and a plurality of feed-through load terminals, a plurality of receptacle load terminals substantially aligned with the plurality of receptacle openings; a separator portion disposed between the back body member and the cover assembly, the separator portion including a reset pin aperture accessible via a first major surface facing the front cover and a reset pin guide portion disposed on an opposite second major surface facing the back body member both being configured to accommodate a reset pin; and a latch block assembly including a central latch block portion configured to accommodate the reset pin and a latching element, the central latch block portion including an open side configured to accommodate the reset pin guide portion, the reset pin being substantially prevented by the reset pin guide portion from exiting the central latch block portion via the open side.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/277,531 filed on May 14, 2014, the contents of which is relied uponand incorporated herein by reference in its entirety, and the benefit ofpriority under 35 U.S.C. § 120 is hereby claimed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electrical wiring devices,and particularly to protective wiring devices.

2. Technical Background

Electric circuits are installed throughout a structure such thatelectrical service is readily accessible to people that live or work inthat structure. An electric circuit includes electrical wires thatinterconnect electrical wiring devices that are positioned at variouslocations throughout a structure. There are a variety of electricalwiring devices available to the consumer including outlet receptacles,light switches, dimmers, ground fault circuit interrupters, arc faultcircuit interrupters and the like.

Ground fault circuit interrupters (GFCIs), transient voltage surgesuppressors (TVSS), surge protective devices (SPDs) and arc faultcircuit interrupters (AFCIs) are examples of electrical protectivedevices. They are used to protect persons and structures from beingharmed by electrical fault conditions. Protective devices are typicallyequipped with a set of interrupting contacts that are used to break theconnection between the line terminals and load terminals when a faultcondition is detected.

With respect to current industry trends, designers of protectiveelectrical wiring devices are faced with two conflicting objectives. Thefirst objective is to reduce the size of the wiring device housing ineach of its three dimensions because smaller wiring devices are easierto install in standard wall box openings. At the same time, consumersare demanding that protective devices include additional protectivecapabilities and/or functionality. For example, many GFCIs now includeself-test circuitry, arc fault prevention circuits, miswire protectioncircuits, and various types of indicator circuitry. Moreover, consumerswant wiring devices that include protective functions in combinationwith non-protective functions. In particular, customers want protectivedevices such as GFCIs, AFCIs, TVSSs, and the like, in combination withone or more electric service devices such as switches, outletreceptacles, various types of sensors, dimmers, night lights, and etc.Briefly stated, customers want more features in a smaller volume.

One consequence of this development is that relatively high voltagecomponents are brought closer to small signal voltage components on asingle printed circuit board. As a result, electrical wiring devicedesigners must now confront the effects of “surface-tracking.” Surfacetracking refers to a failure mode wherein defects and contaminants on,and in, the PCB surface form an undesirable circuit path that causeselectricity and electrical signals to flow where they are not wanted.When electricity is allowed to track across the surface of a PCB, lowvoltage circuits may become short circuited and fail. In addition, ifunwanted electrical currents cause a device to over-heat, a fire couldresult.

Referring back to the customer's desire for more features andfunctionality, many protective devices are now being equipped withmicroprocessors to meet the aforementioned needs. As a result, the highcircuit density noted above may result in AC voltage circuits beingdisposed next to, or proximate, a processor or other such low voltagecircuits. Accordingly, these delicate low voltage signal circuits may besubject to surface-tracking, cross-talk and/or voltage surges. A 6 kVlightning surge, for example, could easily destroy a microprocessor orGFI detector chip.

Another phenomenon that can impact the performance of small signaldevices is cross talk. Cross-talk refers to capacitive orelectro-magnetic coupling, and may also be the result of stray RFsignals or from surface-tracking noise. Cross-talk can be an issuebecause it may affect the calibration of sensitive electrical circuits.GFCI detectors, e.g., are calibrated to trip when a ground fault leakagecurrent is 6 mA or greater. It is imperative that the detector canobtain a true reading on fault current readings because ground faultscan result in human fatalities. With respect to the calibration issue,one must keep in mind that a typical GFI sensor signal is approximatelysix millionths (0.000006 A) of an Ampere. (A toroidal sensor usuallyprovides the signal input to a GFCI detector). One can see, therefore,how large voltage noise signals can make small signal detectionsproblematic.

Various approaches have been tried to reduce the effects of cross-talkand/or surface-tracking. In one approach, the printed circuit board andall of the circuitry thereon are conformally coated. However, this is acostly manufacturing process and it is subject to manufacturingvariabilities. Another approach that has been considered relates to theaddition of notches in the PCB. The notches are positioned to isolatethe low voltage circuitry from the high voltage circuitry. While thisapproach can be effective, it also has drawbacks. For example, arelatively large amount of PCB surface area must be devoted to thenotches, and as a result, the amount of available surface area for theelectronic components can be significantly reduced.

Another issue that is related to device reliability is heat-rise.Devices must operate below a certain temperature or fire may result. Oneof the main causes of heat-rise are the thermal losses (I²R) caused byresistive interconnections in the AC current path. In other words, theelectrical current propagating in the electrical circuit is convertedinto thermal energy (heat). When a device is packed with a large numberof components, it is very practical, from an assembly standpoint, tocreate a conductive path by interconnecting a number of conductivesegments. For example, the practice of routing and interconnecting (hotand neutral) wires through the toroidal assembly results in fourinterconnections, and four sources of heat-rise.

What is needed therefore is a means for substantially mitigating orobviating the effects of surface tracking, cross-talk and voltage surgeswithout using additional PCB surface area. What is further needed is aneffective way to increase the density of electronic components on a PCBwhile maintaining device reliability. In doing so, it is desirable tolimit the number of conductive segments that comprise the AC conductivepath from line to load.

SUMMARY OF THE INVENTION

The present invention addresses the needs described above by providing aprotective device that substantially obviates the threat of surfacetracking and cross-talk from high voltage components to signal voltagecomponents while, at the same time, reducing the PCB surface area.Moreover, the present invention allows for an increase in the density ofelectronic components on a protective device PCB while maintainingdevice reliability. The present invention is also configured tosubstantially prevent voltage surges propagating in the AC electricaldistribution system from damaging small signal components. Inaccomplishing the above stated objectives, the present invention alsolimits the number of conductive segments that comprise the AC conductivepath from line to load to thus limit heat rise.

Generally in one aspect, an electrical wiring device includes: a housingassembly including a cover assembly and a back body member, the coverassembly including a front cover having a plurality of receptacleopenings, the housing assembly further including a plurality of lineterminals and a plurality of feed-through load terminals, the housingassembly also including a plurality of receptacle load terminalssubstantially aligned with the plurality of receptacle openings; aseparator portion disposed between the back body member and the coverassembly, the separator portion including a reset pin apertureaccessible via a first major surface facing the front cover and a resetpin guide portion disposed on an opposite second major surface facingthe back body member both being configured to accommodate a reset pin;and a latch block assembly including a central latch block portionconfigured to accommodate the reset pin and a latching element, thecentral latch block portion including an open side configured toaccommodate the reset pin guide portion, the reset pin beingsubstantially prevented by the reset pin guide portion from exiting thecentral latch block portion via the open side.

According to an embodiment, the latching element is configured to movethe reset pin toward the reset pin guide portion when force is appliedthereto.

According to an embodiment, the device further includes a faultprotection circuit disposed in the back body and substantially disposedon at least one printed circuit board (PCB), the fault protectioncircuit being configured to provide a fault detection stimulus inresponse to detecting at least one type of predetermined faultcondition.

According to an embodiment, the device further includes a circuitinterrupter disposed inside the housing, the circuit interrupterincluding the latch block assembly moveable between a first state and asecond state, the circuit interrupter being configured to place theplurality of line terminals, the plurality of feed-through loadterminals and the plurality of receptacle load terminals in the firststate in response to a reset stimulus and place the plurality of lineterminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in the second state in responseto a fault detection stimulus, the plurality of receptacle loadterminals being connected to the plurality of line terminals and theplurality of feed-through load terminals in the first state and theplurality of receptacle load terminals being electrically isolated fromthe plurality of line terminals and the plurality of feed-through loadterminals in the second state.

According to an embodiment, the circuit interrupter includes a solenoidassembly comprising a solenoid coil and an armature responsive to thefault detection stimulus, the armature being configured to decouple thelatching element from the reset pin.

According to an embodiment, the armature moves the latching elementtoward the reset pin guide portion in response to the fault detectionstimulus.

According to an embodiment, the reset pin guide portion is positioned torestrict movement of the reset pin when the circuit interrupter istransitioning from the first state to the second state.

According to an embodiment, the circuit interrupter further includes aplurality of contact sets configured to be closed in the first state andopen in the second state, at least one contact set of the plurality ofcontact sets being configured to decouple at least a portion of thefault protection circuit assembly from a line terminal of the pluralityof line terminals, in the second state.

According to an embodiment, the contact set includes a moveable contactand a fixed contact, the moveable contact being disposed on a cantilevermember.

Generally in another aspect, an electrical wiring device includes: ahousing assembly including a cover assembly and a back body member, thecover assembly including a front cover having a plurality of receptacleopenings, the housing assembly further including a plurality of lineterminals and a plurality of feed-through load terminals, the housingassembly also including a plurality of receptacle load terminalssubstantially aligned with the plurality of receptacle openings; a resetassembly including a reset button at least partially disposed in thecover assembly and a reset pin; a separator portion disposed between theback body member and the cover assembly, the separator portion includinga reset pin aperture accessible via a first major surface facing thefront cover and a reset pin guide portion disposed on an opposite secondmajor surface facing the back body member configured to accommodate thereset pin; a latch block assembly including a central latch blockportion configured to accommodate the reset pin and a latching element,the central latch block portion including an open side configured toaccommodate the reset pin guide portion, the reset pin guide portionsubstantially preventing the reset pin from exiting the central latchblock portion via the opening; a fault protection circuit disposedinside the housing, the fault protection circuit being configured toprovide a fault detection signal in response to detecting at least onetype of predetermined fault condition; and a circuit interrupterdisposed inside the housing, the circuit interrupter being configured tocouple the plurality of line terminals, the plurality of feed-throughload terminals and the plurality of receptacle load terminals in a firststate in response to a reset stimulus being applied to the reset button,the circuit interrupter being configured to decouple the plurality ofline terminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in a second state when thelatching element and the reset pin are decoupled in response to thefault detection signal.

According to an embodiment, the circuit interrupter includes a solenoidassembly comprising a solenoid coil and an armature responsive to thefault detection signal, the armature being configured to decouple thelatching element from the reset pin when the at least one type of faultcondition is detected.

According to an embodiment, the armature moves the latching elementtoward the reset pin guide portion in response to the fault detectionstimulus.

According to an embodiment, the reset pin guide portion is positioned torestrict movement of the reset pin when the circuit interrupter istransitioning from the first state to the second state.

According to an embodiment, the circuit interrupter further includes aplurality of contact sets configured to be closed in the first state andopen in the second state, at least one contact set of the plurality ofcontact sets being configured to decouple at least a portion of thefault protection circuit assembly from a line terminal of the pluralityof line terminals, in the second state.

According to an embodiment, the contact set includes a moveable contactand a fixed contact, the moveable contact being disposed on a cantilevermember.

According to an embodiment, the circuit interrupter includes a solenoidassembly that affects the second state in response to the faultdetection signal.

According to an embodiment, the circuit interrupter comprises aplurality of moveable bus bars connected to the plurality offeed-through load terminals, a pair of electrical contacts beingdisposed on each of the moveable bus bars.

According to an embodiment, the latch block assembly is configured todrive the plurality of moveable bus bars to the first state.

According to an embodiment, the at least one type of predetermined faultcondition is a ground fault, grounded neutral fault, arc fault, end oflife fault, or auto-test fault.

Generally in a further aspect, an electrical wiring device includes: ahousing assembly including a cover assembly and a back body member, thecover assembly including a front cover having a plurality of receptacleopenings and a separator portion at least partially disposed between theback body member and the front cover, the housing assembly furtherincluding a plurality of line terminals and a plurality of feed-throughload terminals, the housing assembly also including a plurality ofreceptacle load terminals substantially aligned with the plurality ofreceptacle openings; a reset assembly including a reset button at leastpartially disposed in the front cover and a reset pin, the coverassembly including a reset pin aperture accessible via the front coverand a reset assembly guide portion; a latch block assembly including acentral latch block portion configured to accommodate the reset pin anda latching element, the central latch block portion including anopening, the reset assembly guide portion substantially preventing thereset pin from escaping the central latch block portion via the opening;a fault protection circuit disposed inside the housing, the faultprotection circuit being configured to provide a fault detection signalin response to detecting at least one type of predetermined faultcondition; and a circuit interrupter disposed inside the housing, thecircuit interrupter being configured to couple the plurality of lineterminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in a first state in response to areset stimulus being applied to the reset button, the circuitinterrupter being configured to decouple the plurality of lineterminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in a second state when thelatching element and the reset pin are decoupled in response to thefault detection signal.

According to an embodiment, the reset assembly guide portion is disposedon a major surface of the separator portion facing the back body memberand is configured to accommodate the opening of the latch blockassembly.

Generally in another aspect, an electrical wiring device includes: ahousing assembly including a cover assembly and a back body member, thecover assembly including a front cover and a separator portion, thefront cover having a plurality of receptacle openings and at least oneinterface button opening, the cover assembly further including a resetpin aperture and a reset guide portion, the housing assembly furtherincluding a plurality of line terminals and a plurality of feed-throughload terminals, the housing assembly also including a plurality ofreceptacle load terminals substantially aligned with the plurality ofreceptacle openings; a latch block assembly including a central latchblock portion configured to accommodate a reset pin and a latchingelement, the central latch block portion including an opening, the resetassembly guide portion substantially preventing the reset pin fromescaping the central latch block portion via the opening; a faultprotection circuit disposed inside the housing, the fault protectioncircuit being configured to provide a fault detection signal in responseto detecting at least one type of predetermined fault condition; and acircuit interrupter disposed inside the housing, the circuit interrupterbeing configured to couple the plurality of line terminals, theplurality of feed-through load terminals and the plurality of receptacleload terminals in a first state in response to a reset stimulus beingapplied to the reset button, the circuit interrupter being configured todecouple the plurality of line terminals, the plurality of feed-throughload terminals and the plurality of receptacle load terminals in asecond state when the latching element and the reset pin are decoupledin response to the fault detection signal.

According to an embodiment, the at least one interface button opening isconfigured to accommodate a reset button, the reset button beingattached to the reset pin.

According to an embodiment, the reset assembly guide portion is disposedon a major surface of the separator portion facing the back body memberand is configured to accommodate the opening of the latch blockassembly.

Additional features and advantages of the invention will be set forth inthe detailed description which follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary of theinvention, and are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. It should be appreciated that all combinations of the foregoingconcepts and additional concepts discussed in greater detail below(provided such concepts are not mutually inconsistent) are contemplatedas being part of the inventive subject matter disclosed herein. Inparticular, all combinations of claimed subject matter appearing at theend of this disclosure are contemplated as being part of the inventivesubject matter disclosed herein. It should also be appreciated thatterminology explicitly employed herein that also may appear in anydisclosure incorporated by reference should be accorded a meaning mostconsistent with the particular concepts disclosed herein.

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate various embodimentsof the invention and together with the description serve to explain theprinciples and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIGS. 1A-1C are perspective views of the protective electrical wiringdevice in accordance with various embodiments of the present invention;

FIG. 2 is a side elevation view of the protective electrical wiringdevice depicted in FIGS. 1A-1C;

FIG. 3 is a side elevation view of the protective electrical wiringdevice depicted in FIGS. 1A-1C;

FIG. 4 is a perspective view of the protective electrical wiring devicedepicted in FIGS. 1A-1C with various components removed;

FIGS. 5A-5B are perspective views of the line interface assemblydepicted in FIG. 4;

FIG. 6 is an exploded view of the line interface assembly depicted inFIGS. 5A-5B;

FIGS. 7A-7B are detail perspective views of line interface assemblyhousing depicted in FIGS. 5A, 5B and 6;

FIG. 8 is a perspective view of the electro-mechanical assembly depictedin FIG. 4;

FIG. 9 is a perspective view of the circuit interrupter portion of theelectro-mechanical assembly depicted in FIG. 8; and

FIG. 10 is a perspective view of the solenoid actuator assembly depictedin FIG. 9;

FIG. 11 is a perspective view of the latch block assembly depicted inFIG. 9;

FIG. 12 is a detail cross-sectional view of the reset pin guide channelin accordance with an embodiment of the present invention;

FIG. 13 is a cross-sectional view of a protective device in accordancewith another embodiment of the present invention; and

FIG. 14 is a schematic block diagram of the protective device inaccordance with yet another embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the present exemplaryembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.An exemplary embodiment of the protective device of the presentinvention is shown in FIGS. 1A-1C, and is designated generallythroughout by reference numeral 10.

As embodied herein, and depicted in FIGS. 1A-1C, perspective views ofthe protective electrical wiring device in accordance with variousembodiments of the present invention are disclosed. The protectivedevice 10 includes a housing having a front cover 12, a back body member14 and a separator 16. In these embodiments, only a small portion of theseparator 16 can be viewed from the exterior of the device 10 (See, FIG.1B). The front cover includes outlet receptacles 12-1 which areconfigured to accept the hot, neutral and ground blades of a cordedplug. The back body portion 14 includes line screw terminals 102 andload screw terminals 202 that allow the device to be connected to asource of AC power and a load circuit, respectively. FIG. 1B shows theback body portion 14. The rear major surface 14-1 of the back bodyincludes a raised cylindrically shaped portion 14-2 that is configuredto accommodate the toroidal sensor assembly described herein.

As shown herein, the present invention provides the user with variouskinds of indicators. FIG. 1A, e.g., shows an asymmetric recessed portionin the front cover that includes a recessed planar surface 15 that canaccommodate human-readable indicia and one or more indicator lights 20.The indicator lights may be configured as a trip indicator, a pilotlight, a miswire indicator or an end-of-life indicator. Thehuman-readable indicia, therefore, may provide a message or aninstruction appropriate for the light(s). For example, if the light is atrip indicator, the message may read “press reset button ifilluminated.” A reset button 17 and a test button 18 are disposedadjacent to the recessed planar region 15.

In FIG. 1C, the recessed region features a symmetric design withrecessed planar surfaces 15 disposed on either side of the test button18 and reset button 17. The embodiment of FIG. 1C shows an end-of-lifeindicator light 20 with the message “replace if flashing” adjacentthereto.

Referring to FIG. 2, a side elevation view of the protective electricalwiring device 10 is disclosed with the front cover, separator and backbody removed or not shown. A hot receptacle terminal 22-1 is disposedbetween the front cover 12 and the separator 16. (Neither the frontcover nor the separator are shown in this view for clarity ofillustration). The hot receptacle terminal 22-1 includes hot outletreceptacle contacts 22-10, and the neutral receptacle terminal 22-2includes neutral outlet receptacle contacts 22-20. The ground strap 2includes ground contacts 2-2. Altogether, these contacts form two setsof contacts (2-2, 22-10 and 22-20) that accommodate the blades of acorded plug via apertures 12-1 formed in the front cover 12. The hotreceptacle terminal 22-1 also includes hot fixed contact 22-12 that isconfigured to mate with the load-side contact 244-1 of the hot bus bar240-1. The line-side contact 242-1 of the hot bus bar 240-1 mates withthe hot contact 104-10 of the line contact arm 104-1.

Turning now to other elements that are disposed below the separator 16(not shown in this view for clarity of illustration), device 10 isimplemented using a line input interface assembly 100 and anelectro-mechanical assembly 200. Assembly 100 includes a printed circuitboard 101 and the assembly 200 includes another PCB 201 that is offsetfrom the line interface PCB 101. The “PCB Offset” is approximately equalto about 0.25 inches and is configured to prevent cross-talk orsurface-tracking propagating in the line input interface PCB 101 totransfer to the electro-mechanical PCB 201.

As described herein, the line input interface assembly 100 providesdevice 10 with an interface to the line side of the electricaldistribution circuit (i.e., to the AC power source). The line inputinterface assembly 100 may therefore include surge protection,filtering, AC/DC conversion (i.e., power supply circuitry) and otherconditioning circuitry. The toroidal sensors, which are electricallyconnected to circuits on the electromechanical PCB 201, are mounted onthe line input interface assembly PCB 101 such that the line hot andline neutral conductors, along with an optional automatic testconductor, can be routed through the central aperture of the toroids.

The electromechanical PCB 201 includes small signal voltage processingcomponents such as the GFI detector, the microprocessor, etc. Thesolenoid bobbin assembly 210 and latch block 220 are also mechanicallymounted to PCB 201. The solenoid bobbin assembly 210 includes at leastone solenoid coil 212 having at least one interconnect pin electricallyconnected to the line hot conductor. Although the solenoid coil ismechanically attached to PCB 201 as part of bobbin assembly 210, the pinhas little or no electrical connectivity to PCB 201. Instead, the pinpasses through a clearance hole in PCB 201 for electrical connection tothe interface PCB 101. The bobbin assembly may be configured to isolatethe pin from the low voltage circuitry with a wall of plastic. Loadterminals 202 are likewise mounted to electromechanical PCB 201 but withlittle or no electrical connectivity to the board.

Referring to FIG. 3, the side elevation view of the protectiveelectrical wiring device from the opposite side is shown. This viewshows the neutral receptacle terminal 22-2 which includes a neutralfixed contact 22-22 that is configured to mate with a load-side contact244-2 of the neutral bus bar 240-2 (behind light pipe 204-1). Theline-side contact 242-2 of the neutral bus bar 240-2 mates with theneutral contact 104-12 of the line neutral contact arm 104-2. Note thatthe electro-mechanical assembly 200 also includes MOV 206. MOV 206 ispart of a signal conditioning circuit 254 (See, FIG. 14) that alsoincludes an RLC circuit that further protects the solenoid during surgeconditions. The inductor portion of this circuit may be implementedusing the solenoid coil 212. In an alternate embodiment of the presentinvention the resistor, capacitor and MOV 206 may be disposed on theinterface PCB 101 (See, FIG. 14).

As embodied herein and depicted in FIG. 4, a perspective view of theprotective electrical wiring device 10 is shown with the front cover,separator, back body and face receptacle terminals removed. This viewshows an “assembly interface” rectangle—in dashed lines—to show wherethe interface between the line interface assembly 100 and theelectromechanical assembly 200 is located. The interface PCB 101 (notshown in this view) and the electromechanical PCB 201 are interconnectedby the line terminals downstream of the line conditioning components toprovide a conditioned line hot signal for the power supply 270 and aline neutral signal that functions as a local ground reference for thePCB 201. (See, e.g., FIG. 14).

The solenoid bobbin assembly 210 abuts the interface assembly 100 and isflanked on each side by the line contact arms (104-1, 104-2) that extendfrom the line interface assembly 100. The line contact arms (104-1,104-2) include contacts that mate with the line side of the bus bars240-1 and 240-2, respectively. In turn, each bus bar (240-1, 240-2) isconnected to its respective load terminal (202-1, 202-2) by a flex cable(202-3, 202-4), respectively. The bus bars (240-1, 240-2) are configuredto move between the reset state and the tripped state by operation ofthe latch 230 and motion of the latch block 220. The latch block 220includes an auxiliary switch actuator 228 that is configured to operatethe auxiliary switch contacts 234. The region between the load terminals(202-1, 202-2) includes a portion 201-1 of the PCB 201 for small signalcomponents. The microprocessor 252 is disposed on the underside of PCBsection 2011 (and thus is not visible in this view). (See, FIG. 14).

Referring to FIGS. 5A-5B, perspective views of the line interfaceassembly 100 are disclosed. FIG. 5A shows the top side of the lineinterface assembly 100. The line interface assembly 100 includes adielectric, or electrically insulative, housing 110 that has a centralcylindrical portion 114. The central cylindrical portion 114 includes aguide channel 116 that is mounted in the PCB 101 such that it followsthe central cylindrical axis of the center cylindrical portion 114 frombase to base. The central cylindrical portion 114 houses (andsubstantially shields) the toroidal sensor assembly 120 (See FIG. 6).The guide channel 116 includes three passages (116-1, 1162, and 116-3)that accommodate the hot contact arm 104-1, the neutral contact arm1042, and a test circuit conductor 106, respectively. See also, FIGS.7A-7B. As shown in FIG. 5A, the contact arms 104-1 and 104-2 includecontacts 104-10 and 104-20, respectively, which form the line portion ofthe interrupting contact set described below. Furthermore, contact arms104-1 and 104-2 include portions (109-1, 109-2) respectively that arenot electrically isolated by guide channel 116 and spaced apart by a

predetermined distance to form the spark gap 109. Spark gap 109 protectsMOV 108 when there abnormally high energy lightning surges are present.The spark gap 109, therefore, represents another line voltageconditioning element disposed within the interface assembly 100.

FIG. 5B shows the underside of the line interface assembly 100. Thisside of cylindrical portion 114 fits within the raised cylindricallyshaped portion 14-2 of the back body member 14 shown in FIG. 1B. Theguide channel 116 includes a conductor interface portion 118 thatextends through the PCB 101. The contact arms 104-1 and 104-2 emergefrom the guide channel passages (116-1, 116-2) into the conductorinterface element 118 to mate with terminal tabs 102-3 and 102-4,respectively. Note that the screw terminals 102-1 and 102-2substantially conform to terminal support wing portions (112-1, 112-2)which are integrally connected to the cylindrical portion 114. Inparticular, the line hot screw terminal 102-1 wraps around supportportion 1121 and the line neutral screw terminal 102-1 wraps aroundsupport portion 112-2 such that a line hot tab 102-3 and a line neutraltab 102-4, respectively, are positioned within the conductor interfaceelement 118 abutting the end portions of the hot contact arm 104-1 andneutral contact arm 104-2, respectively. At this point, the line hot tab102-3 is electrically joined to the hot contact arm 104-1, and the lineneutral tab 102-4 is electrically joined to the neutral contact arm104-2. Accordingly, there is a single electro-mechanical interconnectionbetween the path that extends from line hot screw terminal 102-1 to theline hot contact 104-10 and a single electro-mechanical interconnectionpath from line neutral screw terminal 102-2 to the line neutral contact104-20. Thus, I²R losses (electricity converted to heat) aresubstantially reduced in the conductive paths between the line screwterminals and the line contacts of the circuit interrupter.

Note that the test conductor 106 also emerges from the interface element118 and is routed to the electro-mechanical assembly 200 where it isconnected to an output of the processor 252. Low voltage signal leads120-1 from the sensors also emerge from a low voltage interface portion111 of the interface housing 110 and are likewise routed to theelectro-mechanical assembly 200 as inputs to the fault detector. See,FIG. 14. Thus, while the toroidal sensor 120 is mechanically mounted tothe PCB 101, the low voltage signal leads from the toroidal sensor areelectrically connected to the electro-mechanical PCB 201. In otherwords, the toroidal sensor 120 is disposed and substantially shieldedfrom noise by the dielectric housing 114, which electrically connects itto the second PCB 201 without introducing noise or cross-talk.

Line tabs (102-3, 102-4) are secured to the first PCB 101 using suitablemeans. A large MOV 108, e.g., 12 mm, is connected between the line hotterminal 102-1 and the line neutral terminal 102-2 in order to conditionthe AC power input signal provided by a source of AC power. The firstPCB 101 may also be configured to include a half-wave rectifier powersupply. In another embodiment of the present invention, the PCB 101 isconfigured to extend a greater distance under the cylindrical portion114 and the terminal support wings 112-1, 112-2 to provide a largersurface area. In this embodiment, the PCB 101 is configured toaccommodate a full-wave bridge rectifier circuit as well as noisemitigating RC filter circuits. In yet another embodiment, the PCB 101 isextended under the PCB 201 to accommodate additional circuitry. See,FIG. 13.

Referring to FIG. 6, an exploded view of the line interface assembly 100depicted in FIGS. 5A-5B is disclosed. The dielectric housing 110 isclearly shown to include the central cylindrical portion 114 and theguide channel 116 disposed along the cylinder's central axis. Theinterface 118 described above is shown at one end of the guide channel116. The interface 118 aligns the line terminals 102 with the contactarms 104 such that the line terminals abut respective contact arms. In asubsequent process step, each line terminal/contact arm pair iselectromechanically connected using suitable means such (e.g.,soldering, etc.). The interface 118 is also configured to be insertedinto an opening 101-2 formed in PCB 101. Finally, the offset between theprinted circuit board 101 and the PCB 201 is substantially establishedby the low voltage interface apron 111 and the bottom of the cylindricalhousing 114.

The toroidal assembly 120 is inserted into the cylindrical housing 114and includes a grounded neutral sensor 122, an insulator 122-1, adifferential sensor 124, another insulator 124-1, and a shield portion126. After the toroid assembly 120 is inserted in cylindrical housing114, the interface portion 118 is inserted into PCB opening 101-2 andthe assembly 110/120 assembly is mechanically mounted to the PCB 101.

Referring to FIGS. 7A-7B, detail perspective views of dielectric housing110 depicted in FIG. 6 is disclosed. FIG. 7A shows the top side of thedielectric housing 110. This view more clearly shows the toroid housing114 and the terminal support wings 112-1, 112-2 described previously.The terminal support wings (112-1, 112-2) are configured to support thecontact arms 104. The guide channel 116 is shown to include a centraldivider 116-4 that is configured to separate the line hot channel 116-1from the line neutral channel 116-2. The central divider portion 116-4also includes a narrower opening 116-3 for the test wire 106. A top viewof the low voltage interface portion 111 is also shown in this view.

FIG. 7B shows the underside of the housing 110. The central cylindricalhousing 114 includes a circular ring 114-1 that is configured toaccommodate the PCB 101. The interface 118 protrudes above the bottomcylinder base 114-2 and the ring 114-1 such that it can be inserted intothe PCB opening 101-2.

As embodied herein and depicted in FIG. 8, a perspective view of themechanical portion 200-2 of the electro-mechanical assembly 200 isdisclosed. As shown above in FIGS. 2-4, the mechanical portion 200-2 isdisposed on the PCB 201 (not shown in this view for clarity ofillustration). The bobbin assembly 210 includes a solenoid coil 212disposed within magnetic frame portion 210-1. As noted above, the bobbinassembly abuts the line interface housing 110 (not shown in this view)and functions as an armature stop for an armature plunger 214 (also notshown in this view).

The latch 230 and coil spring 230-1 are disposed between the solenoidassembly 210 and the latch block 220. The latch 230 includes a verticalstrike plate portion that is engaged by the solenoid armature (not shownin this view) and a horizontal portion that is configured to move withinthe central portion 222 of the latch block 220.

The latch block 220 includes a hot bus bar carrier 224 and a neutral busbar carrier 226 integrally formed and connected to a central latch blockportion 222. The hot carrier 224 includes a central post 224-1 that isconfigured to accommodate a central opening in the hot bus bar 240-1from underneath and a break spring (not shown) from over top. The hotcarrier 224 also includes lateral posts 224-2 and 224-4 that areconfigured to engage the bus bar tab 246-1 therebetween. The bus bar240-1 is also constrained by a raised retainer wall 224-6. (The neutralcarrier 226 includes identical elements).

The hot bus bar 240-1 is electrically connected to the load hot terminal202-1 by flexible cable 202-10. Likewise, the neutral bus bar 240-2 iselectrically connected to the load hot terminal 202-2 by flexible cable202-20. Each bus bar (240) includes contacts (242-1, 242-2) that areconfigured to mate with the line contacts (104-10, 10420) respectively,and contacts (244-1, 244-2) that are configured to mate with thereceptacle contacts (22-12, 22-22) respectively.

As shown by arrow 240-20, the central post (226-1) and the lateral posts(226-2, 226-4) allow one side of the bus bar (240-2) to rotate upwardlywhen the opposite bus bar contact engages with its respective contact(104, or 22). Stated differently, if contact 242-2 engages line armcontact 104-20 first, the bus bar will pivot upwardly from contact 242-2until contact 244-2 engages 22-22 (See, FIG. 3). If contact 244-2engages contact 22-22, the opposite rotation occurs. At the same time,the bus bar tab (246-2) is disposed between the lateral posts (226-2,226-4) that prevent the bus bar from moving laterally. Accordingly, thebus bar contacts are aligned in three dimensions in order tosubstantially minimize arcing and I²R losses.

The mechanical assembly 200-2 also includes an auxiliary switch 234 thatincludes switch throw blade 234-1. The auxiliary switch 234 isconfigured to substantially prevent the GFI circuit (on theelectro-mechanical PCB 201) from receiving conditioned AC power (fromthe line interface PCB 101) when the device is tripped. The processorintegrated circuit continues to receive conditioned power via asecondary power supply. See, FIG. 14.

Referring to FIG. 9, a perspective view of the circuit interrupterportion 220 of the mechanical assembly depicted in FIG. 8 is shown. Inthis view, the bus bars (240-1, 240-2) are removed. Note that the busbar retainer walls 224-6, 226-6 include circular recesses that areconfigured to accommodate a hot break spring and a neutral break spring,respectively. As noted above, the break springs (not shown) are insertedover the central posts (224-1, 226-1) and are configured to apply abreak force to the bus bars when the latch 230 releases the reset pin17-1 (not shown in this view) during a tripping action. The break forceis stored in the break springs when the compressed between the separatorand the bus bars in the reset state. The break force is released whenthe device is tripped. The spring force applied by the break springs, ofcourse, is less than the make force applied by the make spring 17-2coupled to the reset pin 17-1 (See, e.g., FIG. 13).

The latch block 220 also includes an auxiliary switch actuator portion228 that is configured to engage a tab 234-2 that extends from theswitch blade 234-1. When the reset pin 17-1 is released by the latch230, the auxiliary latch block portion 228 engages tab 234-2 to forcethe auxiliary switch contacts 234 to open. When the reset pin engagesthe latch 230 and the make spring lifts the latch block 220 upwardly,the auxiliary switch tab 234-2 is pressed upwardly by an auxiliaryswitch coil spring 204 (not visible in this view) disposed underneath.The coil spring is seated in the back body 14 and extends through anaperture in the apron 210-1. See, e.g., FIG. 12. In an alternateembodiment of the present invention, the switch blade 234-1 may bepre-biased in the closed position as a redundant means for closing theauxiliary switch 234. In yet an alternate embodiment of the presentinvention, the switch blade 234-1 is pre-biased in the closed positionand the auxiliary switch coil spring is omitted.

Referring to FIG. 10, a perspective view of the solenoid actuatorassembly 210 portion of the circuit interrupter depicted in FIG. 9 isdisclosed. The solenoid assembly 210 includes a frame portion 210-2 thataccommodates the solenoid bobbin 212 and the magnetic frame 212-1. Inone embodiment of the invention, solenoid 212 includes a trip solenoidfor normal usage and a second end-of-life (EOL) solenoid that is onlyused when the microprocessor 252 concludes that the device has reachedEOL. The second solenoid may be disposed adjacent to the first solenoidwith a dielectric material disposed therebetween. An armature plunger214 is disposed within the solenoid 212 and is configured to be drivenin an axial direction such that it emerges from the opening 214-2 tostrike the latch 230 when the solenoid is energized. At the other endthereof, the head 214-4 of the armature pin 214 abuts a strike plate114-3 disposed on the toroidal housing 114 (See, FIG. 5A, 7A). The head214-4 normally abuts the strike plate due to the force applied by coilspring 214-6 captured between the head and the magnetic frame 212-1. Ofcourse, when the solenoid is energized to trip the circuit interrupter,the magnetic force overcomes the spring force and the armature movesaway from the strike plate.

The frame portion 210-2 also includes a raised wall 210-3 that definesan opening in the frame 210 that is configured to accommodate the lowercenter portion 222-2 of the latch block 220 (See, FIG. 11). The raisedwall 212-3 includes an opening 210-4 opposite the armature opening214-2; the opening is configured to accommodate the auxiliary coilspring 204 that resets the auxiliary switch blade 234-1 when the latchblock is driven into the reset position. (See, FIG. 13). Switch slot210-5 is configured to accommodate one end of the auxiliary switch blade234-1. The frame portion 210-2 is integrally connected to an apron 210-1that is disposed between the PCB 201 and the respective latch blockcarriers (224, 226). Thus, when the device is tripped, the carriers(224, 226) will rest on the apron 210-1.

Referring to FIG. 11, a perspective view of the latch block assembly 220depicted in FIG. 9 is disclosed. As noted above, the lower centerportion 222-2 of the latch block 220 is configured to be inserted withinthe raised wall 210-3 such that the auxiliary actuator 228 fits withinthe opening 210-4. The center latch block portion 222 is “pi-shaped”(π); the legs are spaced apart and form a central opening 222-1. Asdescribed below, a portion of the separator 16 mates with the opening222-1 to implement a two-piece reset pin guide channel. This designallows for a more compact latch block design in the z-direction, whichin turn, provides for a smaller behind-the-strap device thickness, i.e.,one that is less than one inch. The central latch block portion 222 alsoincludes a horizontal slot that accommodates the latch 230. The latch230 has a rather oblong opening 230-1 instead of the circular openingsthat are commonly employed in the art. The latch 230 also includes astrike plate 230-2 that is engaged by the armature 214 during a trippingaction. Once the solenoid is deenergized, the armature 214 is withdrawnby its coil spring 214-1 allowing the latch coil spring 232 to drive thelatch 230 back into the opening 222-1 until the strike plate 230-2covers the armature opening 214-2 of the magnetic solenoid frame 212-1.

Referring to FIG. 12, a detail cross-sectional view of the reset pinguide channel in accordance with an embodiment of the present inventionis disclosed. The dashed line 16-1 represents an edge of the separatormember 16 whereas the dotted line 222-1 represents the edge of thecenter latch block opening 222-1. The reset pin stem 17-1 is disposedwithin the guide channel formed by these two parts (i.e., between thedashed and dotted lines). This view also provides a clearerrepresentation of the relationship between the auxiliary latch blockactuator 228 and the auxiliary switch blade tab 234-3. Since the samereference numbers are used throughout the drawings to refer to the sameor like parts, no further description is needed for the remaining partsdepicted in this drawing.

As embodied herein and depicted in FIG. 13, a cross-sectional view of aprotective device in accordance with another embodiment of the presentinvention is disclosed. In the previous embodiment, the line interfacePCB 101 was relatively small in size because it might only include a MOVand a half-wave rectifier power supply. In the discussion providedearlier, the present invention disclosed an interface PCB 101 thatcovered the entire interface housing 110. See, FIG. 7B. In thisembodiment, however, the line interface PCB 101 is extended a great dealfarther, i.e., under the electro-mechanical PCB 201 in order toaccommodate more high-voltage conditioning components. As before, thetwo PCBs (101, 201) are discontinuous and offset such that surfacetracking, cross-talk and/or surge currents from the PCB 101 cannotpropagate to PCB 201.

As embodied herein and depicted in FIG. 14, a schematic block diagram ofthe protective device is disclosed that may be implemented using thearrangement depicted in FIG. 13. Because this is a schematicrepresentation, it shows the electrical connections but not necessarilythe mechanical implementation. Thus, as before, the toroidal sensors122, 124 are physically mounted on the line interface PCB 101, but arein reality, only connected to components disposed on PCB 201. In thedual-solenoid arrangement (212, 213), the solenoids are mounted on thelow voltage board 201 (as shown above), but electrically connected tothe high voltage AC line hot conductor 102-1. Thus, the solenoids areshown on the interface PCB 101 for clarity of illustration of theelectrical interconnections.

The protective device 10 includes a differential transformer 122 whichis configured to sense load-side ground faults, i.e. ground faultslocated in loads connected to load terminals (202) or receptaclecontacts (22). Transformer 124 is configured as a grounded neutraltransmitter that is configured for grounded-neutral fault detection.Both differential transformer 122 and grounded-neutral transformer 124are coupled to the fault detector 250 by small signal interconnectionsbetween PCB 101 and PCB 201. Detector 250 receives power from a dualpower supply circuit 270 that may be disposed on either PCB. The outputof the detector 250 is connected to the control input of SCR Q1. WhenSCR Q1 is turned ON, the solenoid 212 is energized to actuate thecircuit interrupter 220 such that the circuit interrupter 220 and theauxiliary switch 234 are tripped (opened). Solenoid 212 remainsenergized for a time period that is typically less than about 25milliseconds. When the circuit interrupter 220 trips, the line terminals102 are disconnected from their respective load terminals (202) orreceptacle contacts (22). After the fault condition has been eliminated,the circuit interrupter 220 may be reset by way of a reset button 17(See, e.g., FIGS. 1A-C).

The grounded neutral transmitter 124 is configured to detect a groundedneutral condition. (The line neutral conductor 2 is typically groundedin the electrical circuit at the panel—this does not constitute agrounded neutral fault condition). When a grounded neutral condition isnot present, the grounded neutral transmitter 124 is configured tocouple equal signals into the hot and neutral conductors. Because thedifferential transformer 122 is configured to sense a currentdifferential, the equal signals provided by the grounded neutraltransmitter 124 effectively cancel each other out. On the other hand, agrounded neutral condition does occur when the load neutral conductor(i.e., the conductor that is connected to the load neutral terminal orthe neutral receptacle contact) is accidentally grounded. This creates aparallel conductive path (relative to the neutral return path) betweenthe neutral line terminal and neutral load terminal. As a result,another signal circulates around this current loop and it is coupledonto the neutral conductor (but not the hot conductor) to create adifferential current. The differential transformer 122 senses thedifferential current between the hot and neutral conductors and thedetector 250 generates a fault detection signal to actuate SCR Q1,energize solenoid 212 and trip the circuit interrupter 220.

In one embodiment of the invention, device 10 is equipped with arc-faultprotection and includes an arc-fault circuit interrupter (AFCIprotection). AFCIs are configured to detect high frequency disturbances(indicative of arcing) superimposed on the power line frequency. Thehigh frequency disturbances may occur in the load current, the linevoltage, or both. Thus, the interface assembly 100 may include atoroidal load current sensor 125 and/or a voltage divider 126. Inanother embodiment, the interface assembly 100 may include a loadcurrent monitor (LCM) 127 featuring a shunt or a Hall Effect device.Since an arc fault condition may create a path between the hot conductorto ground, a differential sensor may be employed to sense this type offault. As shown in FIG. 14, the current sensors (125, 127) and thevoltage sensor 126 are coupled to the fault detector 250 so that thecircuit interrupter can be tripped when an arc fault is detected.Reference is made to U.S. Pat. Nos. 6,362,628; 6,373,257; 6,538,863; and6,876,528, which are is incorporated herein by reference as though fullyset forth in its entirety, for a more detailed explanation of thecurrent and voltage sensors and/or the arc fault detector. Based on theforegoing, those skilled in the art will appreciate that fault detector250 may be configured to detect arc fault conditions, ground faultconditions, or both. In yet another embodiment of the invention a loadcurrent sensor module (LCM) 127 may be coupled to the load hot tomeasure the load current. LCM 127 may be implemented using a Hall Effectsensor or a resistive shunt.

After the fault signal is removed the circuit interrupter 220 may bemanually reset by way of a reset button 17 (not shown). Auxiliary switch234 opens when circuit interrupter 220 is in the tripped state andcloses when the circuit interrupter is in the reset state.

In reference to the power supply circuit 270, it is provided toaccommodate the needs of the detection function (described above). Anindependently operable end of life (EOL) power supply circuit 272accommodates the needs of the universal auto-test function. Reference ismade to U.S. patent application Ser. No. 13/834,636, which isincorporated herein by reference as though fully set forth in itsentirety, for a more detailed explanation of a power supply 270 inaccordance with one aspect of the present invention. When the device 10detects a fault condition, it is configured to interrupt the circuitinterrupter 220 during the positive half-cycle of the AC line cycle. Inorder to meet the trip time requirements, the second power supplyportion of power supply 270 is configured to charge to the full supplyvoltage in less than about 2 milliseconds. This means that during thepositive half cycles, a hazardous ground fault condition is detected andinterrupted quickly.

The microprocessor 252 generates a simulated grounded neutral testsignal by way of wire loop 254 when a FET is turned ON. When the FET isturned ON, the grounded neutral transmitter 124 produces an oscillatingsignal that is a function of the full power supply voltage. The ON stateresistance of the FET is less than about 4 Ohms. Thus, the wire loop254, in combination with the FET (in the ON state), form a loop thatpasses through the differential transformer 122 and neutral transmitter124 to simulate a grounded neutral condition. One advantage for placingthe third wire within the wire loop relates to improved noise immunity.When the third wire is employed, the wire loop 254 and the neutralconductor are isolated such that the current propagating in wire loop254 during the self-test is not affected by voltage drops or electricalnoise propagating in the neutral conductor. Noise propagating on theneutral conductor could otherwise impair the test fault signal and itsdetection by the GFCI.

The timing of the FET ON state is controlled by a timing resistor or byprocessor 252. (The FET and the timing resistor are depicted as circuitelement 254-1 in FIG. 14). In one embodiment of the present invention,the FET is turned ON near the conclusion of the positive half cycle ofthe AC power source and remains ON through a portion of the negativehalf cycle to produce the test fault signal. The grounded neutraltransformer 124 generates a differential current in response to the testcurrent propagating in wire loop 254. The differential current is, inturn, sensed by transformer 122. If the circuit is working properly, thesensor signal provided by 122 should be deemed by detector 250 as afault. Since the auto-test is performed during the negative half cycleor late in the positive half cycle such, SCR Q1 will not be turned ONand the device will not nuisance trip.

The power supply 270 is shown as being in series with the auxiliaryswitch 234 and the solenoid 212 on PCB 201. Note that power supply 270may be included on PCB 201, along with other small signal voltageprocessing components, because the signal conditioner 256 (PCB 101)provides it with conditioned power signals. The signal conditioningcircuit 256 includes a secondary MOV and other signal conditioningcircuitry such as an RC filter circuit and/or an RLC filter circuit.When the auxiliary switch 234 is closed, the inductance of the solenoid212 protects the power supply 270 from lightning surges that couldotherwise damage the protective device (AFCI/GFCI). Thus, PCB 101provides PCB 201 with a conditioned, i.e., protected, AC circuit. Inother words, surface tracking, cross talk and surge voltages aresubstantially prevented from propagating from PCB 101 to PCB 201 by thePCB board discontinuities and offset, the large MOV 108 disposed betweenthe line terminals 102, the solenoid 212, and the conditioning circuit256. Those skilled in the art will also appreciate that anotherconditioning circuit may be employed with solenoid 213. It is notdepicted herein for clarity of illustration. The auxiliary switch 234 isconfigured to protect the solenoid 212 should SCR Q1 short out byinterrupting power to the low voltage PCB 201 when the circuitinterrupter 220 trips. Likewise, the auxiliary switch 234 protects theother solenoid 213.

Thus, device 10 may include MOV 108 and two additional movistorsdisposed in the signal conditioning circuits 256. The movistors, ofcourse, are configured to protect the GFCI from lighting surges. SinceMOV 108 is disposed across-the-line it is relatively large (12 mm) inorder to withstand surges. Since the movistors in the conditioningcircuit 256 are disposed in series with the solenoid 212 and theself-test solenoid 213, respectively, they may be relatively smaller insize (e.g., 5-7 mm). The inductances of the dual solenoids 212, 213serve as a high frequency filter that limits the surge energy that theconditioning circuit MOVs must absorb in the event of a lightningstrike.

As described herein, the low voltage PCB 201 includes a microprocessor252 disposed thereon. In one embodiment the microprocessor 252 may beimplemented by a processor such as the Renesas R5F10266. Themicroprocessor 252 provides a 1 MHz clock signal that is used fordigital clocks and other internal timing signals. The microprocessor 252may include 2 kB ROM to store the firmware and 2 KB Flash memory toimplement the wiring state register (for miswire detection).

It will be apparent to those of ordinary skill in the pertinent art thatmodifications and variations can be made to the processor 40 of thepresent invention depending on the degree of processing sophistication.The embedded processor 252 includes on-board memory that typicallyincludes random access memory (RAM) and read only memory (ROM). Theembedded processor 252 functions may be implemented using hardware,software, embedded processors, signal processors, RISC computers,application specific integrated circuits (ASICs), field programmablegate array (FPGA) devices, gate array state machines, customizedintegrated circuits and/or a combination thereof. The RAM memory mayhave battery back-up. Thus, the embodiments of the present invention arenot limited to any specific combination of hardware circuitry and/orsoftware. Taken together, RAM and ROM may be referred to herein as“computer-readable media.” The term “computer-readable medium,” as usedherein, refers to any medium that participates in providing data and/orinstructions to the processor for execution. For example, thecomputer-readable media employed herein may include any suitable memorydevice including SRAM, DRAM, NVRWM, PROM, E²PROM, Flash memory, or anysuitable type of memory. The Flash memory or RAM with battery back-upare examples of non-volatile memory that is provided herein to store thewiring state of the device for multi-use miswire purposes.

One of the functions of the processor 252 is to orchestrate a two-stepself-testing regimen. In the first step, processor 252 tests a portionof the protective circuit that includes sensors (122, 124, 125 or 127),fault detector 250, power supply 270, SCR Q1, and solenoid 212 byproviding a simulated ground fault signal, a grounded neutral fault, oran arc fault to the sensor(s). The processor 252 monitors the anode ofSCR Q1 in order to determine if the fault detection circuitry isoperational. Because the SCR Q1 is actuated during a time frame when itcannot energize the solenoid, the device is prevented from tripping.This signal is registered by the processor 252 as a test acceptancesignal, i.e., the protective device (AFCI/GFCI) is working properly.Every time the SCR anode goes low, an internal “end-of-life” timer inprocessor 252 is reset. The anode input is also coupled to a filtercircuit that removes high frequency noise that might falsely indicatethat the device 10 passed the end of life test. If the end-of-life timeris not reset within the preprogrammed time frame, it signals the CPU inprocessor 252 that and end-of-life condition has been reached. The CPUcauses LED 204 to be illuminated and further causes SCR Q2 to trip thecircuit interrupter 220 after a predetermined time period has elapsed.

In the second step of the self-testing regimen, a test signal is appliedby processor 252 to the gate of the SCR to test the operability of theSCR and the solenoid. As in the first step, the test signal is timed sothat the response signal does not cause circuit interrupter 220 tonuisance trip. By way of illustration, the response signal may occurlate in a half cycle where the line voltage is too low to causetripping, or during the negative half cycles of the line voltage whenthe protective circuit is configured to trip only during the positivehalf cycles.

In the dual-solenoid arrangement depicted in FIG. 14, a failed self-testresults in the circuit interrupter being tripped by redundant solenoid213. In a single solenoid embodiment of the present invention, solenoid213 is omitted and SCR Q2 is connected to trip the circuit interrupter220 by way of solenoid 212. In another single solenoid embodiment, bothsolenoid 213 and SCR Q2 are omitted and processor 250 is configured totrip the interrupter by way of SCR Q1. Reference is made to U.S. Pat.No. 6,421,214, which is incorporated herein by reference as though fullyset forth in its entirety, for a more detailed explanation of an end oflife detection circuit in accordance with yet another embodiment of thepresent invention.

The indicator 204 is shown as a visual indicator (LED), but thoseskilled in the art will appreciate that it may be implemented as anaudible indicator or as both an audible and visual indicator. Inalternate embodiment, after an end of life condition is detected, theindicator 204 may provide a cyclical or oscillating indication to alertthe user that power denial is imminent. After a predetermined interval,the power denial is implemented to trip the device. Once tripped, thedevice cannot be reset. In another embodiment the device can be reset,however, it will trip again after another predetermined interval. FIG.14 depicts a pilot indicator light 203 that is configured to emitillumination when voltage is provided to line terminals 102. The pilotindicator is fed by unconditioned power and is thus disposed on theinterface PCB 101.

As shown, the processor 252 is coupled to a redundant processor powersupply 272 that derives power from the line side of the interruptingcontacts instead of indirectly through auxiliary switch 234. Theredundant processor power supply 272 allows the self-test circuit tooperate if there is an end of life condition in the power supply 270.Moreover, note that GFCI power supply 270 is deenergized in the trippedstate, but since the processor 252 has its own power supply 272, it isfunctional in the tripped state.

The present invention provides miswiring protection capabilities. Onlyone bit of non-volatile memory is required for this function althoughthe system memory may include more. The one-bit memory, i.e., the wiringstate register, is used to store the wiring state of the device.(1=proper wiring, 0=miswiring). Thus, when the wiring state registerstores a ONE (1), the processor 252 allows the circuit interrupter 222to be reset (assuming that an end-of life state is not extant). However,if the wiring state register is LOW, it indicates a miswired conditionand the circuit interrupter 222 cannot remain reset because theprocessor will keep tripping the interrupter until the proper wiring isachieved and the memory bit is set to a HIGH state. As described above,the wiring state register is implemented using flash memory in oneembodiment of the invention.

While the device is being manufactured, one of the final assembly stepsbefore the device enters the stream of commerce is to write a logic zerointo the wiring state register. Reference is made to U.S. patentapplication Ser. No. 13/834,636, which is incorporated herein byreference as though fully set forth in its entirety, for a more detailedexplanation of the wiring state detection register and procedure.[00101] The present invention uses an integrated approach to protectinglow signal voltage devices such as fault detectors, microprocessors, andthe like from damage from surface-tracking, cross-talk, and surgevoltages. For example, the two PCBs (101, 201) are discontinuous andoffset about 0.25 inches. Moreover, the line interface PCB 101 includesseveral layers of protective circuitry that provide PCB 201 conditionedpower signals. In other words, surface tracking, cross talk and surgevoltages are substantially prevented from propagating from PCB 101 toPCB 201 by the PCB board discontinuities and offset, and the protectiveconditioning circuitry described herein. [00102] While several inventiveembodiments have been described and illustrated herein, those ofordinary skill in the art will readily envision a variety of other meansand/or structures for performing the function and/or obtaining theresults and/or one or more of the advantages described herein, and eachof such variations and/or modifications is deemed to be within the scopeof the inventive embodiments described herein. More generally, thoseskilled in the art will readily appreciate that all parameters,dimensions, materials, and configurations described herein are meant tobe exemplary and that the actual parameters, dimensions, materials,and/or configurations will depend upon the specific application orapplications for which the inventive teachings is/are used. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, many equivalents to the specific inventiveembodiments described herein. It is, therefore, to be understood thatthe foregoing embodiments are presented by way of example only and that,within the scope of the appended claims and equivalents thereto;inventive embodiments may be practiced otherwise than as specificallydescribed and claimed.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

It should also be understood that, unless clearly indicated to thecontrary, in any methods claimed herein that include more than one stepor act, the order of the steps or acts of the method is not necessarilylimited to the order in which the steps or acts of the method arerecited.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about” and “substantially”, are not to be limited tothe precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value. Here and throughout the specification andclaims, range limitations may be combined and/or interchanged; suchranges are identified and include all the sub-ranges contained thereinunless context or language indicates otherwise.

The recitation of ranges of values herein are merely intended to serveas a shorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein.

All methods described herein can be performed in any suitable orderunless otherwise indicated herein or otherwise clearly contradicted bycontext. The use of any and all examples, or exemplary language (e.g.,“such as”) provided herein, is intended merely to better illuminateembodiments of the invention and does not impose a limitation on thescope of the invention unless otherwise claimed.

No language in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. There isno intention to limit the invention to the specific form or formsdisclosed, but on the contrary, the intention is to cover allmodifications, alternative constructions, and equivalents falling withinthe spirit and scope of the invention, as defined in the appendedclaims. Thus, it is intended that the present invention cover themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

What is claimed is:
 1. An electrical wiring device comprising: a housingassembly including a cover assembly and a back body member, the coverassembly including a front cover having a plurality of receptacleopenings, the housing assembly further including a plurality of lineterminals and a plurality of feed-through load terminals, the housingassembly also including a plurality of receptacle load terminalssubstantially aligned with the plurality of receptacle openings; aseparator portion disposed between the back body member and the coverassembly, the separator portion including a reset pin apertureaccessible via a first major surface facing the front cover and a resetpin guide portion disposed on an opposite second major surface facingthe back body member both being configured to accommodate a reset pin;and a latch block assembly including a central latch block portionconfigured to accommodate the reset pin and a latching element, thecentral latch block portion including an open side configured toaccommodate the reset pin guide portion, a distal end of the reset pinbeing positioned distally to a distal end of the latching element whenin a reset position, and the reset pin being substantially prevented bythe reset pin guide portion from exiting the central latch block portionvia the open side.
 2. The device of claim 1, wherein the latchingelement is configured to move the reset pin toward the reset pin guideportion when force is applied thereto.
 3. The device of claim 1, furthercomprising a fault protection circuit disposed in the back body andsubstantially disposed on at least one printed circuit board (PCB), thefault protection circuit being configured to provide a fault detectionstimulus in response to detecting at least one type of predeterminedfault condition.
 4. The device of claim 3, further comprising a circuitinterrupter disposed inside the housing, the circuit interrupterincluding the latch block assembly moveable between a first state and asecond state, the circuit interrupter being configured to place theplurality of line terminals, the plurality of feed-through loadterminals and the plurality of receptacle load terminals in the firststate in response to a reset stimulus and place the plurality of lineterminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in the second state in responseto a fault detection stimulus, the plurality of receptacle loadterminals being connected to the plurality of line terminals and theplurality of feed-through load terminals in the first state and theplurality of receptacle load terminals being electrically isolated fromthe plurality of line terminals and the plurality of feed-through loadterminals in the second state.
 5. The device of claim 4, wherein thecircuit interrupter includes a solenoid assembly comprising a solenoidcoil and an armature responsive to the fault detection stimulus, thearmature being configured to decouple the latching element from thereset pin.
 6. The device of claim 5, wherein the armature moves thelatching element toward the reset pin guide portion in response to thefault detection stimulus.
 7. The device of claim 4, wherein the resetpin guide portion is positioned to restrict movement of the reset pinwhen the circuit interrupter is transitioning from the first state tothe second state.
 8. The device of claim 4, wherein the circuitinterrupter further includes a plurality of contact sets configured tobe closed in the first state and open in the second state, at least onecontact set of the plurality of contact sets being configured todecouple at least a portion of the fault protection circuit assemblyfrom a line terminal of the plurality of line terminals, in the secondstate.
 9. The device of claim 8, wherein the contact set includes amoveable contact and a fixed contact, the moveable contact beingdisposed on a cantilever member.
 10. An electrical wiring devicecomprising: a housing assembly including a cover assembly and a backbody member, the cover assembly including a front cover having aplurality of receptacle openings, the housing assembly further includinga plurality of line terminals and a plurality of feed-through loadterminals, the housing assembly also including a plurality of receptacleload terminals substantially aligned with the plurality of receptacleopenings; a reset assembly including a reset button at least partiallydisposed in the cover assembly and a reset pin; a separator portiondisposed between the back body member and the cover assembly, theseparator portion including a reset pin aperture accessible via a firstmajor surface facing the front cover and a reset pin guide portiondisposed on an opposite second major surface facing the back body memberconfigured to accommodate the reset pin; a latch block assemblyincluding a central latch block portion configured to accommodate thereset pin and a latching element, the central latch block portionincluding an open side configured to accommodate the reset pin guideportion, the reset pin guide portion substantially preventing the resetpin from exiting the central latch block portion via the opening, adistal end of the reset pin being positioned distally to a distal end ofthe latching element when in a reset position; a fault protectioncircuit disposed inside the housing, the fault protection circuit beingconfigured to provide a fault detection signal in response to detectingat least one type of predetermined fault condition; and a circuitinterrupter disposed inside the housing, the circuit interrupter beingconfigured to couple the plurality of line terminals, the plurality offeed-through load terminals and the plurality of receptacle loadterminals in a first state in response to a reset stimulus being appliedto the reset button, the circuit interrupter being configured todecouple the plurality of line terminals, the plurality of feed-throughload terminals and the plurality of receptacle load terminals in asecond state when the latching element and the reset pin are decoupledin response to the fault detection signal.
 11. The device of claim 10,wherein the circuit interrupter includes a solenoid assembly comprisinga solenoid coil and an armature responsive to the fault detectionsignal, the armature being configured to decouple the latching elementfrom the reset pin when the at least one type of fault condition isdetected.
 12. The device of claim 11, wherein the armature moves thelatching element toward the reset pin guide portion in response to thefault detection stimulus.
 13. The device of claim 10, wherein the resetpin guide portion is positioned to restrict movement of the reset pinwhen the circuit interrupter is transitioning from the first state tothe second state.
 14. The device of claim 10, wherein the circuitinterrupter further includes a plurality of contact sets configured tobe closed in the first state and open in the second state, at least onecontact set of the plurality of contact sets being configured todecouple at least a portion of the fault protection circuit assemblyfrom a line terminal of the plurality of line terminals, in the secondstate.
 15. The device of claim 14, wherein the contact set includes amoveable contact and a fixed contact, the moveable contact beingdisposed on a cantilever member.
 16. The device of claim 10, wherein thecircuit interrupter includes a solenoid assembly that effects the secondstate in response to the fault detection signal.
 17. The device of claim10, wherein the circuit interrupter comprises a plurality of moveablebus bars connected to the plurality of feed-through load terminals, apair of electrical contacts being disposed on each of the moveable busbars.
 18. The device of claim 17, wherein the latch block assembly isconfigured to drive the plurality of moveable bus bars to the firststate.
 19. The device of claim 10, wherein the at least one type ofpredetermined fault condition is a ground fault, grounded neutral fault,arc fault, end of life fault, or auto-test fault.
 20. An electricalwiring device comprising: a housing assembly including a cover assemblyand a back body member, the cover assembly including a front coverhaving a plurality of receptacle openings and a separator portion atleast partially disposed between the back body member and the frontcover, the housing assembly further including a plurality of lineterminals and a plurality of feed-through load terminals, the housingassembly also including a plurality of receptacle load terminalssubstantially aligned with the plurality of receptacle openings; a resetassembly including a reset button at least partially disposed in thefront cover and a reset pin, the cover assembly including a reset pinaperture accessible via the front cover and a reset assembly guideportion; a latch block assembly including a central latch block portionconfigured to accommodate the reset pin and a latching element, thecentral latch block portion including an opening , the reset assemblyguide portion substantially preventing the reset pin from escaping thecentral latch block portion via the opening, a distal end of the resetpin being positioned distally to a distal end of the latching elementwhen in a reset position; a fault protection circuit disposed inside thehousing, the fault protection circuit being configured to provide afault detection signal in response to detecting at least one type ofpredetermined fault condition; and a circuit interrupter disposed insidethe housing, the circuit interrupter being configured to couple theplurality of line terminals, the plurality of feed-through loadterminals and the plurality of receptacle load terminals in a firststate in response to a reset stimulus being applied to the reset button,the circuit interrupter being configured to decouple the plurality ofline terminals, the plurality of feed-through load terminals and theplurality of receptacle load terminals in a second state when thelatching element and the reset pin are decoupled in response to thefault detection signal.
 21. The device of claim 20, wherein the resetassembly guide portion is disposed on a major surface of the separatorportion facing the back body member and is configured to accommodate theopening of the latch block assembly.
 22. An electrical wiring devicecomprising: a housing assembly including a cover assembly and a backbody member, the cover assembly including a front cover and a separatorportion, the front cover having a plurality of receptacle openings andat least one interface button opening, the cover assembly furtherincluding a reset pin aperture and a reset guide portion, the housingassembly further including a plurality of line terminals and a pluralityof feed-through load terminals, the housing assembly also including aplurality of receptacle load terminals substantially aligned with theplurality of receptacle openings; a latch block assembly including acentral latch block portion configured to accommodate a reset pin and alatching element, the central latch block portion including an opening,the reset assembly guide portion substantially preventing the reset pinfrom escaping the central latch block portion via the opening, a distalend of the reset pin being positioned distally to a distal end of thelatching element when in a reset position; a fault protection circuitdisposed inside the housing, the fault protection circuit beingconfigured to provide a fault detection signal in response to detectingat least one type of predetermined fault condition; and a circuitinterrupter disposed inside the housing, the circuit interrupter beingconfigured to couple the plurality of line terminals, the plurality offeed-through load terminals and the plurality of receptacle loadterminals in a first state in response to a reset stimulus being appliedto the reset button, the circuit interrupter being configured todecouple the plurality of line terminals, the plurality of feed-throughload terminals and the plurality of receptacle load terminals in asecond state when the latching element and the reset pin are decoupledin response to the fault detection signal.
 23. The device of claim 22,wherein the at least one interface button opening is configured toaccommodate a reset button, the reset button being attached to the resetpin.
 24. The device of claim 22, wherein the reset assembly guideportion is disposed on a major surface of the separator portion facingthe back body member and is configured to accommodate the opening of thelatch block assembly.